Pad for skin preparation for electrocardiography and the like



J. R. SMITH May 19, 1959 PAD FOR SKIN PREPARATION FOR ELECTROCARDIOGRAPHY AND THE LIKE Filed Aug. 15, 1957 2 Sheets-Sheet 1 INVENTOR. Jaw P. 5/11/76 Arrozmms' May19, 1959 J. R. SMITH 2,887,112

PAD FOR SKIN PREPARATION FOR ELECTROCARDIOGRAPHY AND THE LIKE Filed Aug. 15, 1957 2 Sheets-Sheet 2 To necrnacnnmoannpn INVENTOR. -J0///v 19. Sin/r11 ATTORNEYS United States Patent PAD FOR SKIN PREPARATION FOR ELECTRO- CARDIOGRAPHY AND THE LIKE John R. Smith, Winchester, Mass., assignor to Sanborn Company, Waltham, Mass, a corporation of Massachusetts Application August 15, 1957, Serial No. 678,409

Claims. (Cl. 128-417) The present invention relates to pads for preparing the skin and the like for electrocardiographic and similar measurements.

It has long been recognized that, when electrodes are applied to the skin for electrocardiographic measurements, the skin-to-electrode barrier should be of as low electrical resistance as possible. Resort has accordingly been had to numerous techniques and devices for reducing this resistance. The oil on the skin, of course, should be removed if low resistance is to be attained. The skin and the electrode itself, for example, have thus been cleaned as by swabbing with alcohol. It is particularly important that no metallic or similar particles be trapped under the electrode since such particles cause local electrolytic action that makes the recorded base line of the electrocardiograph unsteady. Electrode jelly or paste or electrolytic solution is then applied to the skin to serve as a low-resistance path contacting the skin and the electrode. An edge of the electrode itself, however, is customarily scraped over the skin several times to abrade the same and dilate the skin vessels, which phenomenon has been found to improve the electrical conductivity of the skin. This application of the electrolytic jelly or solution is, at best, a messy procedure, resulting in the coating of parts of the electrical cables, corroding of the electrodes, and soiling of the finger tips of the operator. The art has had to put up these long years, however, with the carrying of containers or tubes of electrode paste and the attendant inconvenience in dispensing and cleaning off of the tubes; the preparation of special electrolyte solutions and the saturating of towels and the like to apply the solution to the skin; or the filling with electrolyte of special absorbent containers associated with the electrodes. The numerous additional cleaning and skin-rubbing steps, above-mentioned, moreover, have also had to be employed.

An object of the present invention, accordingly, is to provide a novel pad that can be conveniently carried and stored in a dry state, and then used without any of the disadvantages, above discussed.

A further object is to provide a new and improved technique for preparing the skin for electrocardiographic and similar measurements.

Other and further objects will be explained hereinafterand will be more particularly pointed out in the appended claims.

The invention will now be described in connection with the accompanying drawing Fig. 1 of which is an enlarged fragmentary view of a pad constructed in accordance with a preferred embodiment of the invention; and

Figs. 2 through 4 are schematic views of successive steps involved in employing the pad for electrocardiographic and similar measurements, the dimensions of the .pad of Fig. 2 being exaggerated for clarity of illustration.

Fig. 1 is a reproduction of a microscopic view of a portion of a pad 2 constructed so as to embody the present invention in preferred form. As illustrated, the pad 2,887,112 Patented May 19, 1959 2 comprises one or more layers of a preferably gauzelike fiber matte, the fibers 4 of which are disposed in matrix form, defining a plurality of interstices or openings 6. Adhering to the fibers 4 and within thejopenings 6, is a hardened non-corrosive paste or jelly binder containing solid particles 8 of a salt, such as sodium chlo- I ride, that, in solution, exhibits electrolytic action. Also interposed within the binder 10 and heldto the fibers 4 and within some of the openings 6 therebetween, are fine solid abrasive particles 12, such as, for example, 60- to IOU-mesh quartz particles, which are insoluble in water. The pad 2 may be prepared, for example, through appropriately impregnating the same with the above-mentioned binder containing the salt and abrasive particles and then heating the pad to dry it into a relatively rigid or stiff member. The dry pad 2 will have a high electrical resistance.

Dry pads 2 may be packaged for shipment and storage as, for example, in groups of a few to an envelope, for the use of an individual electrocardiograph patient. Alternatively, the pads may be provided in tapes, rolls or sheets, preferably appropriately scored for facilitating the obtaining of a pad of appropriate size for use with an electrode, as later discussed.

When it is desired to use the dry rigid pad 2, it may first be somewhat wetted, as with water droplets 14, Fig. 2. The hardened paste or jelly binder 10 will readily soften and the salt or similar solid particles 8 will readily dissolve, rendering the pad thoroughly moistened with electrolyte and thus of low electrical resistance. The mechanical stiffness of the somewhat wetted pad 2 will permit it to serve as a carrier for the abrasive non-soluble quartz or other particles 12 so that the operator may rub the pad 2 against the skin, such as the wrist 1 or other portion of the body of the patient, Fig. 3, thus abrading the same and, in one single operation, both cleaning the skin and abrading the same to produce an erythema that dilates the skin vessels. It has been found, moreover, that the pad 2, in its wetted condition, appears to retain the bulk of the impregnant binder and its particle contents, yet loses none of the desired electrical. characteristics of low resistance. The moistened low-resistance pad 2 may then be placed between the cleaned and abraded wrist 1 and the electrode 3, with the electrode 3 strapped or clamped to the wrist, as at 5, and connected by a conductor or cable 7 to the electrocardiograph or similar apparatus.

Not only has the inconvenience and messiness of the prior-art techniques been completely obviated by the present invention, but the necessity for separate skin cleaning and abrading steps has been completely eliminated, also. After use, moreover, it has been found that the moistened pad 2 leaves the wrist 1 and the electrode 3 almost dry, as contrasted with the coatings of jelly, paste or other electrolyte as presently employed. At the completion of the test, the pads 2 may be disposed of, and whatever slight smear that may be left upon the wrist 1 or other portion of the body and on the electrode 3 may be readily wiped off. Corroding of the electrodes or coating the electric cable 7 or other parts of the equip ment with excess jelly, paste or electrolyte is also avoided. The operator, moreover, maintains his fingers relatively clean, when preparing, applying and removing the pad 2. In addition, a definite sanitary appeal is provided.

While the invention has been described in connection with a gauze-like or cheesecloth type of carrier, other kinds of absorbent fibers, or plastic carriers, such as Fiberglas mattes and the like, may also be employed, providing, preferably, a measure of stitfness satisfactory for the abrading step of Fig. 3. Though the use of a binder 10 is preferred, the salt or other electrolyte-forming particles 8 may be applied in solution and then dried upon serr te l the fibers 4; or otherwise" secured" thereto. of abrasives than the preferred quartz particles 12 may also be employed, though they should be insoluble so as to" re r'nain solid during and following the wetting step of Fig. 2'. Very close, as well as wider mesh carriers may be employed? v I Further modifications will occur to those skilled in the art and all such are co'nside'red to fall within the spirit and scope of theinvention as defined in the appended claims.

What'is claimed is: v

1. A dry relatively high electrical resistance pad for preparing the skin and the like for electrocardiographic and similar measurements, comprising a stifi matte to' which are adhered ja plurality of solid particles of the type that, when dissolved'insolution; produce electrolytic action, interspersed with] a' plurality of nonsoluble abra s-ive particles, the matte having sufiicient mechanical strength, when wetted, to serve as a carrier for rubbing the said abrasive particles against the skin and the like to abrade the same, and the said solid particles being readily soluble upon wetting the matte to render the pad of relatively low electrical resistance.

2. A dry relatively high electrical resistance pad for preparing the skin and the like forelectrocardiographic and similar measurements, comprising a stiti matte to which is adhered a hardened paste containing a plurality of solid particles of the type that, when dissolved in solu tion, produce electrolytic action, interspersed with a plurality of non-soluble abrasive particles, the matte having sufiicient mechanical strength, when wetted, to serve as a carrier for rubbing the said abrasive particles against the skin and the likekto abrade the same, and the said paste being readily softened and the said solid particles readily soluble upon wetting the matte to render the pad of relatively low electrical resistance.

3. A dry relatively high electrical resistance pad for preparing the skin and the like for electrocardiographic and similar measurements, comprising a stiff fibrous matte having a plurality of openings between the fibers, and, adherent to the fibers and within certain of the said open ings, a plurality of solid particles of the type that, when dissolved in solution, produce electrolytic action, inter- Other types spersed with a'plurality ofnon-soluble abrasive particles, the matte having sufficient'" mechanical strength, when wetted, to serve as a carrier for rubbing the said abrasive particles against the skin and the like to abrade the same, and the said solid particles being readily soluble upon wetting the matte to render the'pad of relatively low electrical resistance;

4. A dry relatively high electrical resistance pad for preparing the skin and the like for electrocardiographic and similar measurements, comprising a stiff, fibrous matte having a plurality of openings between the fihers, and, adherent to the fibers and within certain of the said openings, a hardened paste containing a plurality of solid particles of the type that, when dissolved-in solution, produce electrolytic action, interspersed with a plurality of non-soluble abrasive particles, the matte having suflioient mechanical strength, whenwetted, to serve as a carrier for rubbing the said abrasive particles against the skin and the like to abrade the same, and the said paste being readily softened and the said solid particles readily soluble upon wetting the matte to render the pad of relatively low electrical resistance.

5. A dry relatively high electrical resistance pad for preparing the skin and the like for electrocardiographic and similar measurements, comprising a stilt fibrous gauze matte having a plurality of openings between the fibers, and, adherent to the fibers and Within certain of the said openings, a hardened paste containing a plurality of solid salt particles of the type that, when dissolved in solution, produce electrolytic action, interspersed with a plurality of non-soluble abrasive quartz particles, the

References Cited in the file of this patent UNITED STATES PATENTS 2,782,786 Krasno Feb. 26, 1957 Kimble Jan. 29, 1935 

